Asencio, 28, is 1-2 with a 5.23 ERA in 39 major league games spread over three seasons with the Atlanta Braves, Cleveland Indians and Chicago Cubs. He signed with the Brewers as a minor league free agent Nov. 5 and appeared in one spring training game, allowing two runs and one hit, with two walks, without retiring a batter.
Asencio was 0-1 with a 1.35 ERA in 13 games and 13 1/3 innings with Triple-A Iowa last season.
The Orioles will assign Asencio to Triple-A Norfolk. He signed a minor league deal and won't be placed on the 40-man roster.
The Orioles had interest in Asencio last year and scouted him in La Romana in the Dominican Winter League.
"He's been on the fringe of the major leagues," said executive vice president Dan Duquette. "He's got good stuff. A good fastball and split-finger or forkball that he relies on. And he's been successful in the Dominican Winter League closing out games, and also in Triple-A. He's more pitching depth and a potential major league bullpen pitcher.
"I just felt he would be helpful. Sometimes, it takes a little bit longer. He's another guy who doesn't give up a lot of home runs and throws the ball over the plate."
Asencio spent the entire 2010 season on the Braves' restricted list because of visa issues. It was later discovered that he had used a false name, Luis Valdez, and birthday.
Duquette also said the club isn't certain whether Wilson Betemit will require surgery on his right knee after being diagnosed today with a Grade 2/3 tear in his PCL and associated injuries.
"We'll have to take a closer look at that," he said. "It will probably take some time for him to return to playing form."
For now, the Orioles intend to look internally for Betemit's replacement.
"I kind of like the players we have in camp," Duquette said. "I think we have good depth and complementary strengths with the players we have in camp. Wilson's strength is his left-handed bat against right-handed pitching, but (Ryan) Flaherty's got a good bat left-handed, and some other guys we have hit right-handed pitching pretty well, like Nolan (Reimold)is pretty good against right-handed pitching and Chris Dickerson looks pretty good, too. And I think Steve Pearce is leading the Grapefruit League in home runs, isn't he?
"This should be an opportunity for another player we have in camp to make the club."